Re: how to use the uninstalled C & C++ compilers?

[Jakub Jelinek <jakub at redhat dot com>]

On Tue, Mar 31, 2015 at 09:37:27PM +0200, Matthias Klose wrote:
> On 03/31/2015 01:09 PM, Matthias Klose wrote:
> > In the past (at least it worked for me in 4.9) it was possible to use the
> > uninstalled C & C++ compilers to build another compiler, using the just built
> > compilers.  Useful if you want to build e.g. libgccjit in a second step without
> > bootstrapping again.  This doesn't seem to work anymore with 5. At least I can't
> > get it working by removing the system c++ and g++ after the build of the first
> > compiler and then building as
> > 
> > CC=$(builddir)/gcc/xgcc -B$(builddir)/gcc/
> > CXX=$(builddir)/gcc/xg++ -B$(builddir)/gcc/ \
> >     -I$(builddir)/$(TARGET_ALIAS)/libstdc++-v3/include \
> >     -I$(builddir)/$(TARGET_ALIAS)/libstdc++-v3/include/$(TARGET_ALIAS)
> > 
> > and the next build (without bootstrapping) with these values. Did somebody got
> > this working?  Sometimes it looks like gcc is built using the C compiler,
> > sometimes it doesn't find the "new" header, and probably won't find the
> > libstdc++ library later. Not setting CXX seems to silently use the g++ system
> > compiler if it exists.
> 
> this is what is now working for me.
> 
>   CC = $(builddir)/gcc/xgcc -B$(builddir)/gcc/
>   CXX = $(builddir)/gcc/xg++ -B$(builddir)/gcc/ \
>         -B$(builddir)/$(TARGET_ALIAS)/libstdc++-v3/src/.libs \
>         -B$(builddir)/$(TARGET_ALIAS)/libstdc++-v3/libsupc++/.libs \
>         -I$(builddir)/$(TARGET_ALIAS)/libstdc++-v3/include \
>         -I$(builddir)/$(TARGET_ALIAS)/libstdc++-v3/include/$(TARGET_ALIAS) \
>         -I$(srcdir)/libstdc++-v3/libsupc++ \
>         -L$(builddir)/$(TARGET_ALIAS)/libstdc++-v3/src/.libs \
>         -L$(builddir)/$(TARGET_ALIAS)/libstdc++-v3/libsupc++/.libs

I'm using
CC="`$${builddir}/libstdc++-v3/scripts/testsuite_flags --build-cc`"
CXX="`$${builddir}/libstdc++-v3/scripts/testsuite_flags --build-cxx` `$${builddir}/libstdc++-v3/scripts/testsuite_flags --build-includes`"
instead and it works for me.

	Jakub